#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

/*******************************************************************************
printf()
putchar()
puts()

fprintf()
putc()
fputs()

sprintf()
*******************************************************************************/

static FILE *fp = NULL;


int main(int argc, char *argv[])
{
    printf("Hello World!\r\n");

    if ((fp = fopen("output.txt", "r)) == NULL) {
        printf(" ERROR: open file fail!!!\r\n");
        exit(1);
    }

    //...

    fclose(fp);

    system("pause");
    return 0;
}
